Note 3 - Investment Securities Available-for-Sale (Tables)

9 Months Ended

Sep. 30, 2015

Investments, Debt and Equity Securities [Abstract]

Schedule of Available-for-sale Securities Reconciliation [Table Text Block]

			Gross		Gross		Estimated
September 30, 2015	Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value
U. S. Government agency securities	$	68,289	$	879	$	90	$	69,078
Residential mortgage backed securities		320,978		2,172		1,130		322,020
Municipal bonds		114,137		3,824		95		117,866
Corporate bonds		15,096		-		78		15,018
Other equity investments		307		37		-		344
	$	518,807	$	6,912	$	1,393	$	524,326

			Gross		Gross		Estimated
December 31, 2014	Amortized		Unrealized		Unrealized		Fair
(dollars in thousands)	Cost		Gains		Losses		Value
U. S. Government agency securities	$	29,434	$	500	$	40	$	29,894
Residential mortgage backed securities		241,120		1,716		2,516		240,320
Municipal bonds		106,983		4,850		121		111,712
Other equity investments		396		21		-		417
	$	377,933	$	7,087	$	2,677	$	382,343

Schedule of Unrealized Loss on Investments [Table Text Block]

	Less than				12 Months
	12 Months				or Greater				Total
	Estimated				Estimated				Estimated
September 30, 2015	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(dollars in thousands)	Value		Losses		Value		Losses		Value		Losses
U. S. Government agency securities	$	13,966	$	90	$	-	$	-	$	13,966	$	90
Residential mortgage backed securities		58,925		182		61,610		948		120,535		1,130
Municipal bonds		12,073		95		-		-		12,073		95
Corporate bonds		15,018		78		-		-		15,018		78
	$	99,982	$	445	$	61,610	$	948	$	161,592	$	1,393

	Less than				12 Months
	12 Months				or Greater				Total
	Estimated				Estimated				Estimated
December 31, 2014	Fair		Unrealized		Fair		Unrealized		Fair		Unrealized
(dollars in thousands)	Value		Losses		Value		Losses		Value		Losses
U. S. Government agency securities	$	2,001	$	7	$	1,750	$	33	$	3,751	$	40
Residential mortgage backed securities		49,644		221		86,028		2,295		135,672		2,516
Municipal bonds		4,974		14		10,915		107		15,889		121
	$	56,619	$	242	$	98,693	$	2,435	$	155,312	$	2,677

Available-for-sale Securities [Table Text Block]

	September 30, 2015				December 31, 2014
	Amortized		Estimated		Amortized		Estimated
(dollars in thousands)	Cost		Fair Value		Cost		Fair Value
U. S. Government agency securities maturing:
One year or less	$	44,981	$	45,138	$	2,998	$	3,051
After one year through five years		18,812		19,259		19,947		20,276
Five years through ten years		4,496		4,681		6,489		6,567
Residential mortgage backed securities		320,978		322,020		241,120		240,320
Municipal bonds maturing:
One year or less		4,978		5,024		2,410		2,438
After one year through five years		40,040		42,600		47,038		49,607
Five years through ten years		66,539		67,456		54,983		56,927
After ten years		2,580		2,786		2,552		2,740
Corporate bonds
After one year through five years		15,096		15,018		-		-
Other equity investments		307		344		396		417
	$	518,807	$	524,326	$	377,933	$	382,343